Method of demodulation of a stereophonic signal

1. A method for demodulating a multiplexed stereophonic signal, the signal comprising:

a sum signal, which is a sum of two monophonic signals,

a difference signal, which is a difference of said two monophonic signals, and

a pilot signal at a pilot frequency serving as a reference for performing a frequency transposition of the difference signal on the basis of a carrier signal, the method comprising:

removing the pilot frequency from the multiplexed stereophonic signal, to form a pilotless signal comprising the sum signal and the difference signal; and

subtracting the sum signal from the pilotless signal, to form an untransposed difference signal.

2. The method as claimed in claim 1 , wherein a rejection filter is used in the step of removing the pilot frequency.

3. The method as claimed in claim 1 , comprising applying a delay to the pilotless signal prior to the subtraction step.

4. The method as claimed in claim 1 , comprising a step of regenerating the carrier signal on the basis of the multiplexed stereophonic signal and the pilotless signal.

5. A method for demodulating a multiplexed stereophonic signal, the signal comprising:

a sum signal, which is a sum of two monophonic signals,

a difference signal, which is a difference of said two monophonic signals, and

a pilot signal at a pilot frequency serving as a reference for performing a frequency transposition of the difference signal on the basis of a carrier signal, the method comprising:

removing the pilot frequency from the multiplexed stereophonic signal, to form a pilotless signal; and

subtracting the sum signal from the pilotless signal, to form an untransposed difference signal,

wherein the step of regenerating the carrier signal comprises a subtraction step in which the pilotless signal is subtracted from the multiplexed stereophonic signal, the subtraction step being followed by a step of applying a delay.

6. The method as claimed in claim 5 , wherein the step of regenerating the carrier signal comprises a step of using a phase-locked loop subsequent to the step of applying a delay.

7. The method as claimed in claim 6 , wherein the step of regenerating the carrier signal comprises a step of doubling the pilot frequency subsequent to the step of using a phase-locked loop.

8. The method as claimed in claim 7 , wherein the step of regenerating the carrier signal comprises a step of filtering by a band-pass filter, subsequent to the step of doubling the frequency, the resulting signal being called the regenerated carrier signal.

9. The method as claimed in claim 4 , comprising a step of multiplying the untransposed difference signal and the regenerated carrier signal.

10. The method as claimed in claim 9 , next comprising a step of filtering by a low-pass filter so as to recover the difference signal.

11. A method for demodulating a multiplexed stereophonic signal, the signal comprising:

a sum signal, which is a sum of two monophonic signals,

a difference signal, which is a difference of said two monophonic signals, and

a pilot signal at a pilot frequency serving as a reference for performing a frequency transposition of the difference signal on the basis of a carrier signal, the method comprising:

removing the pilot frequency from the multiplexed stereophonic signal, to form a pilotless signal;

subtracting the sum signal from the pilotless signal, to form an untransposed difference signal; and,

filtering by a low-pass filter prior to the step of subtracting the pilotless signal from the sum signal.

12. The method as claimed in claim 11 , comprising a step of recovering the sum signal by applying a delay to the signal resulting from the step of filtering by a low-pass filter prior to the step of subtracting the pilotless signal from the sum signal.

13. The method as claimed in claim 2 , comprising applying a delay to the pilotless signal prior to the subtraction step.